Summary: Chemicals are selected to be antibiotics based on their capability to cure disease with minimal side effects. (The ability to restrict the emergence of resistance has not been a criterion for antibiotic selection.) Chemicals that kill pathogens were first developed by Paul Ehrlich early in the Twentieth Century. Subsequently, Alexander Fleming discovered that secretions from a mold killed bacteria, an observation that led to the discovery of penicillin. Gerhard Domagk found sulfa drugs in the 1930s. Most antibiotics interfere with central life processes, such as synthesis of DNA, RNA, protein, cell membranes, and cell walls. Because human cells also carry out these processes, except for cell wall formation, a challenge is to find agents t....Antiseptics